Bump manifest to 1.5.2.
Bump manifest to 1.5.2.

manastungare/google-calendar-crx,manastungare/google-calendar-crx,YOTOV-LIMITED/google-calendar-crx,thanhpd/google-calendar-crx,ChaosEngine/google-calendar-crx,CooperLuan/google-calendar-crx,Steindi01/google-calendar-crx,CooperLuan/google-calendar-crx,bonaime/google-calendar-crx,Steindi01/google-calendar-crx,bonaime/google-calendar-crx,thanhpd/google-calendar-crx,YOTOV-LIMITED/google-calendar-crx,ChaosEngine/google-calendar-crx